3,515 research outputs found
Comment to "Observation of the neutron radiative decay" by R.U. Khafizov et al., published in JETP Letters 83 (2006) 5 (Pis'ma v ZhETF 83 (2006) 7)
The commented manuscript was submitted for publication without informing at
least four of the other authors, viz. N. Severijns, O. Zimmer, H.-F. Wirth and
D. Rich. This violates our rights as collaborators. The analysis presented and
the manuscript itself have not been discussed and have also not been approved
by the entire collaboration prior to submission. Besides this formal
incorrectness, we also criticise the content of the paper
3-D-Analyse von posttraumatischen Tibiaschaftfehlstellungen und deren Korrektur anhand der gesunden Gegenseite
OBJECTIVE: Three-dimensional (3D) analysis and implementation with patient-specific cutting and repositioning blocks enables correction of complex tibial malunions. Correction can be planned using the contralateral side or a statistical model. Patient-specific 3D-printed cutting guide blocks enable a precise osteotomy and reduction guide blocks help to achieve anatomical reduction. Depending on the type and extent of correction, fibula osteotomy may need to be considered to achieve the desired reduction.
CONTRAINDICATIONS: a) Poor soft tissue (flap surgery, adherent skin in field of operation); b) infection; c) peripheral artery disease (stage III and IV classified according to Fontaine, critical transcutaneous oxygen partial pressure, TcPO); d) general contraindication to surgery.
SURGICAL TECHNIQUE: Before surgery, a 3D model of both lower legs is created based on computed tomography (CT) scans. Analysis of the deformity based on the contralateral side in a 3D computer model (CASPA) and planning of the osteotomy. If the contralateral side also has a deformity, a statistical model can be used. Printing of patient-specific guides made of nylon (PA2200) for the osteotomy and reduction. Surgery is performed in supine position, antibiotic prophylaxis, thigh tourniquet, which is used as needed. Ventrolateral approach to the tibia. Attachment of the patient-specific osteotomy guide, performance of the osteotomy. Reduction using the guide. Fibula osteotomy through a lateral approach is performed if the reduction of the tibia is hindered by the fibula. This can be performed freehand or with patient-specific guides. Wound closure.
POSTOPERATIVE MANAGEMENT: Compartment monitoring. Passive mobilization of the ankle in the cast as soon as the wound healing has progressed. Partial weightbearing in a lower leg cast for at least 6-12 weeks, depending on the routinely performed radiographic assessment 6 weeks postoperatively. Thromboprophylaxis with low molecular weight heparin until cast removal.
RESULTS: Patient-specific correction of malunions are generally good. This could be confirmed for distal tibial corrections. For tibial shaft deformities, the final results are still pending. Preliminary results, however, show good feasibility with a pseudarthrosis rate of 10% without postoperative infection
Lifshitz transitions and quasiparticle de-renormalization in YbRhSi
We study the effect of magnetic fields up to 15 T on the heavy fermion state
of YbRhSi via Hall effect and magnetoresistance measurements down to 50
mK. Our data show anomalies at three different characteristic fields. We
compare our data to renormalized band structure calculations through which we
identify Lifshitz transitions associated with the heavy fermion bands. The Hall
measurements indicate that the de-renormalization of the quasiparticles, {\it
i.e} the destruction of the local Kondo singlets, occurs smoothly while the
Lifshitz transitions occur within rather confined regions of the magnetic
field.Comment: 7 pages, 5 figure
Role of cross-shell excitations in the reaction 54Fe(d_pol,p)55Fe
The reaction 54Fe(d_pol,p)55Fe was studied at the Munich Q3D spectrograph
with a 14 MeV polarized deuteron beam. Excitation energies, angular
distributions and analyzing powers were measured for 39 states up to 4.5 MeV
excitation energy. Spin and parity assignments were made and spectroscopic
factors deduced by comparison to DWBA calculations. The results were compared
to predictions by large scale shell model calculations in the full pf-shell and
it was found that reasonable agreement for energies and spectroscopic factors
below 2.5 MeV could only be obtained if up to 6 particles were allowed to be
excited from the f_7/2 orbital into p_3/2, f_5/2, and p_1/2 orbitals across the
N=28 gap. For levels above 2.5 MeV the experimental strength distribution was
found to be significantly more fragmented than predicted by the shell model
calculations.Comment: 9 pages, 12 figures, 3 tables, submitted to European Physical Journal
Hybridization gap and Fano resonance in SmB
We present results of Scanning Tunneling Microscopy and Spectroscopy (STS)
measurements on the "Kondo insulator" SmB. The vast majority of surface
areas investigated was reconstructed but, infrequently, also patches of varying
size of non-reconstructed, Sm- or B-terminated surfaces were found. On the
smallest patches, clear indications for the hybridization gap and
inter-multiplet transitions were observed. On non-reconstructed surface areas
large enough for coherent co-tunneling we were able to observe clear-cut Fano
resonances. Our locally resolved STS indicated considerable finite conductance
on all surfaces independent of their structure.Comment: 5 pages, 4 figure
0+ states and collective bands in 228Th studied by the (p,t) reaction
The excitation spectra in the deformed nucleus 228Th have been studied by
means of the (p,t)-reaction, using the Q3D spectrograph facility at the Munich
Tandem accelerator. The angular distributions of tritons were measured for
about 110 excitations seen in the triton spectra up to 2.5 MeV. Firm 0+
assignments are made for 17 excited states by comparison of experimental
angular distributions with the calculated ones using the CHUCK3 code.
Assignments up to spin 6+ are made for other states. Sequences of states are
selected which can be treated as rotational bands and as multiplets of
excitations. Moments of inertia have been derived from these sequences, whose
values may be considered as evidence of the two-phonon nature of most 0+
excitations. Experimental data are compared with interacting boson model and
quasiparticle-phonon model calculations and with experimental data for 229Pa.Comment: 21 pages, 14 figure
Disorder-driven electronic localization and phase separation in superconducting Fe1+yTe0.5Se0.5 single crystals
We have investigated the influence of Fe-excess on the electrical transport
and magnetism of Fe1+yTe0.5Se0.5 (y=0.04 and 0.09) single crystals. Both
compositions exhibit resistively determined superconducting transitions (Tc)
with an onset temperature of about 15 K. From the width of the superconducting
transition and the magnitude of the lower critical field Hc1, it is inferred
that excess of Fe suppresses superconductivity. The linear and non-linear
responses of the ac-susceptibility show that the superconducting state for
these compositions is inhomogeneous. A possible origin of this phase separation
is a magnetic coupling between Fe-excess occupying interstitial sites in the
chalcogen planes and those in the Fe-square lattice. The temperature derivative
of the resistivity drho/dT in the temperature range Tc < T < Ta with Ta being
the temperature of a magnetic anomaly, changes from positive to negative with
increasing Fe. A log 1/T divergence of the resistivity above Tc in the sample
with higher amount of Fe suggests a disorder driven electronic localization.Comment: 7 page
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